7.2 Lifting equipment hazards and control measures

Question 1

The main categories of lifting equipment are

Answer 1

cranes and hoists

Question 2

Three types of crane are specified on the NEBOSH Diploma syllabus:

Answer 2

 Mobile cranes  Tower cranes… used extensively on construction sites Overhead cranes … used in engineering works / industrial settings

Question 3

The choice of a suitable crane depends upon: 5

Answer 3

 The characteristics of the load to be lifted.  The selection of suitable lifting accessories (the weight of the lifting accessories must be taken into account when sizing the crane).  The crane position, where the load is to be lifted from, the route that the load will take during the lift, and where it will be landed.  Constraints on erection and dismantling.  Site and environmental constraints (such as headroom or load bearing capacity).

Question 4

Site and environmental constraints include: 9

Answer 4

 Ground conditions.  Underground hazards - open or backfilled excavations - drainage pipes - tunnels - services - basements.  Overhead cables.  Distance of the crane from the structure under construction, adjacent buildings, roads and pedestrian accesses from which clearance must be maintained.  Prevailing weather conditions and exposure of the site: - wind loading - ice and snow loading.  Route to, and access on to, the site for the crane and vehicles delivering the load.  Space for final positioning and safe operation of the crane: - deployment of the outriggers - room for slewing.  Clearance to railway tracks and overhead catenaries.  Clearance to aircraft in the vicinity of airfields (Aircraft warning lights may be required).

Question 5

The two principal hazards associated with crane use are:

Answer 5

 The crane collapsing (due to overloading) or toppling (due to ground conditions or overloading / overreaching), which presents significant potential for multiple fatal injuries, both on and off-site.  The load falling (as a result of inadequate slinging, the load snagging or failure of the lifting accessories / tackle), which has a significant potential for death and major injury. Other significant hazards include:  Moving loads striking pedestrians vehicles or structures.  Cranes contacting overhead conductors or other overhead obstructions.  Cranes colliding with other cranes, other site plant, structures or people.

Question 6

Before siting the crane careful consideration should be given to the range factors that could affect its safe operation, such as: 5

Answer 6

 the standing and support conditions  the presence and proximity of other hazards  the need to oversail neighbouring property  the effect of wind during in-service and out-of-service conditions  the adequacy of access to allow the placing or erection of the crane in its working position and for dismantling and removing the crane following completion of lifting operations.

Question 7

The three basic factors affecting the stability of a crane in use are:

Answer 7

 Load combinations and their relation to the centre of gravity of the crane (see below)  The support arrangement, i.e. ground conditions, foundations and any tying in arrangements (discussed earlier).  Operator control.

Question 8

Crane – technical safeguards The following safety devices should be fitted: 6

Answer 8

Rated capacity indicator (RCI)Rated capacity indicator (RCI)Motion limit devices (MLD)Overload cut out devicesLevel indicatorAnemometer (wind-speed measuring devices)

Question 9

All lifting operations should be planned so they are carried out safely with foreseeable risks taken into account. The lifting plan should be developed by a competent person with adequate practical and theoretical knowledge, and experience of the lifts being undertaken. The plan should address: 3

Answer 9

 the risks identified by a risk assessment  the resources required  procedures and responsibilities to ensure the lifting operation is carried out safely.

Question 10

LOLER guidance Safe use of lifting equipment (L113) offers the following advice on the key features of a basic lifting plan. 8

Answer 10

(a) Assess the weight of the load. (b) Choose the right accessory for lifting, depending upon the nature and weight of the load and the environment in which it is to be used. (c) Check the anticipated path of the load to make sure that it is not obstructed. (d) Prepare a suitable place to set down the load. (e) Fit the sling to the load (using an appropriate method of slinging). (f) Make the lift (a trial lift may be necessary to confirm the centre of gravity of the load and tag lines may be necessary to stop the load swinging). (g) Release the slings (boards or similar may be necessary to prevent trapping of the sling). (h) Clear up.

Question 11

The appointed person is responsible for ensuring that all lifting operations are planned to ensure that they are carried out safely and that all foreseeable risks have been taken into account. The planning process should take into account: 6

Answer 11

 The load, its characteristics and the method of lifting.  The selection of a suitable crane(s).  The selection of suitable accessories for lifting/lifting attachments.  The position of the crane(s) and of the load before, during and after the operation.  The site of the operation including proximity hazards, space availability and suitability of the ground or foundations.  Any necessary erection and dismantling of the crane(s).

Question 12

Method statements Once the risk assessment has been completed, the appointed person should ensure that a full method statement is prepared, detailing the safe system of work and including the risk assessment. The method statement should include: 4

Answer 12

 The tasks to be achieved, together with the configuration of the crane at the end of each day’s work.  Details of the steps to be taken to eliminate danger to personnel not involved in the lifting operation, and where necessary, prevent their entry into danger zones by, for example, organising for road closures if necessary.  The requirement for pre-use checks to be completed.  A clear statement of the allocation of tasks to all parties involved in the lifting operation.

Question 13

Safe system of work A safe system of work should be established and followed for every crane installation operation or lifting operation, whether it be an individual lift or a group of repetitive operations. The safe system of work should be communicated to all parties concerned and should include: 9

Answer 13

(a) Planning of the operation. (b) Selection, provision and use of a suitable crane(s) and work equipment. (c) Site preparation for the erection and dismantling of the crane(s). (d) Maintenance, examination and testing of the crane(s) and equipment. (e) The provision of properly trained and competent personnel. (f) Adequate supervision. (g) Availability of thorough examination reports and other documents. (h) Preventing unauthorised movement or use. (i) The safety of persons not involved in the installation or lifting operation.

Question 14

Duties of the appointed person The appointed person’s duties should include the following. 7

Answer 14

 Being familiar with the relevant parts of the project Health and Safety Plan, where the lifting operation is being carried out on a site where the CDM Regulations apply.  Assessing the lifting operation to provide such planning, selection of crane(s), lifting accessories and equipment, instruction and supervision as is necessary for the task to be undertaken safely.  Ensuring that adequate inspection/examination and maintenance of the equipment has been carried out.  Ensuring that there is an effective procedure for reporting defects and incidents and taking any necessary corrective action.  Taking responsibility for the organisation and control of the lifting operation.  Ensuring that the crane supervisor is fully briefed on the contents of the method statement.  On sites where there is a possibility of collision between cranes and other equipment, the crane coordinator should plan the sequence of crane movements to prevent collisions.

Question 15

A basic lift is one where the weight of the load(s) can be simply established, and there are no hazards or obstructions within the area of the operation. In such cases the appointed person should: 13

Answer 15

 Establish the weight of the load. This can be by referring to a reliable source of information, by weighing the load, or by calculation (with allowance for possible inaccuracies).  Select an appropriate crane, based on the weight of the load, including the crane hook block and any lifting tackle, the maximum height of lift and the maximum radius required.  Consider the location of the operation, taking into account the access and egress required for the crane and the suitability of the ground to take the loads imposed on the crane during preparation and during the lift itself.  Ensure that the crane is not operated in wind speeds in excess of manufacturer’s recommendation.  Ensure that the crane has been thoroughly examined at least within the previous 6 months (for lifting of persons) or 12 months (including testing where appropriate), and inspected and checked before use.  Ensure that a defect reporting system is in place.  Select appropriate lifting accessories, including their method of attachment to the load.  Ensure that lifting accessories have been thoroughly examined within the previous 6 months and inspected and checked before use.  Ensure that the lifting accessories and any lifting points on the load are checked to ensure they are free from any obvious defect before attaching the load to the crane.  Brief all persons involved in the lifting operation to ensure that the safe system of work described in the method statement is understood.  Designate persons to handle handlines / taglines ID required to control the load.  Check, if numerous loads are to be lifted over a long period, that no changes are required in the safe system of work.  Ensure that there is a crane supervisor designated to direct personnel, and that the operation is carried out in accordance with the method statement.

Question 16

(a) Outline a range of factors that may cause instability of a mobile crane. 8 marks (b) Outline control measures that should be taken to reduce the likelihood of a mobile crane overturning during a lifting operation. 12 marks

Answer 16

(a) Factors affecting crane stability that could have been outlined include issues connected with the load, those affecting the crane directly such as lateral or longitudinal stability and other stability issues. Issues connected with the load include:  its weight and centre of gravity  incorrect slinging  snatching of the load or shock loading  the load snagging on obstructions. Instability issues which might affect the crane directly include:  unstable ground that is incapable of bearing the weight of the crane and its load  sloping or uneven ground  outriggers not fully extended and a failure to use spreader plates  exceeding the crane’s safe working load  overruling the rated capacity indicator and/or alarm  slewing or hoisting too quickly. Other stability issues include:  travelling on gradients under load  driving too fast or extending the jib under load  incorrect rigging of the luffing jib, blocks or sheaves  incorrect tyre pressures  mechanical failure  inadvertent contacts  adverse weather conditions. (b) Control measures that should be taken involve initially the carrying out of an area survey including a full assessment of the environment such as ground conditions including the presence of voids, excavations or soft ground; overhead and proximity hazards; weather forecasts and pre-lift levelling and compaction. This will be followed by procedural control measures such as:  the preparation of a lifting plan and the appointment of a competent person to supervise the lift  ensuring that the statutory inspections and certification of the crane have been carried out and that it has been regularly maintained  the selection of the correct lifting accessories  cordoning off the lifting area and erecting warning signs and carrying out a test lift. Additionally it will be necessary to ensure that the appropriate engineering controls are in place and are in good working condition such as a rated capacity indicator and alarm system, speed limiters, the over-hoist limit switch and the motion and performance limit device; to ensure the outriggers are fully extended and positioned on spreader plates; and that visibility is improved where necessary by the provision of CCTV and/or mirrors. Finally consideration will have to be given to behavioural controls such as the competence and training of the driver, slinger and banksman.

Question 17

The Lifting Operations and Lifting Equipment Regulations 1998 specify fixed intervals between thorough examinations of lifting equipment but also includes an option for thorough examination to be carried out in accordance with an ‘examination scheme’. Outline the factors that a competent person would need to take into account when deciding whether less frequent examinations might be justified. 10 marks

Answer 17

Factors which the competent person would need to take into account include:  the age of the equipment  the standards and specifications to which the equipment had been designed and manufactured, and the quality conformance of materials at the time of manufacture  the manufacturers’ recommendations on testing, inspection and maintenance, and whether there has been compliance with these recommendations  the history of the equipment including the extent of use, the loads lifted and the environments in which it has been used, and its current and anticipated future use  the equipment’s accident, breakdown and repair history, including the records of modifications, alterations and the fitting of replacement parts, and the typical performance history of similar items of equipment  the records of previous thorough examinations  any insurance company requirements.